Lymph node blood vessels provide exit routes for metastatic tumor cell dissemination in mice

An alternate route for metastatic cells Metastatic tumor cells are thought to reach distant organs by traveling through the blood circulation or the lymphatic system. Two studies of mouse models now suggest a hybrid route for tumor cell dissemination. Pereira et al. and Brown et al. used distinct methodologies to monitor the fate of tumor cells in lymph nodes. They found that tumor cells could invade local blood vessels within a node, exit the node by entering the blood circulation, then go on to colonize the lung. Whether this dissemination route occurs in cancer patients is unknown; the answer could potentially change the way that affected lymph nodes are treated in cancer. Science , this issue p. 1403 , p. 1408